library(boot)
AUC <- function(Yx,ind){
  phat <- fitted(glm(Yx[ind,1]~Yx[ind,-1]))
  pc <- sort(unique(phat))
  n2 <- length(pc)
  m2 <- matrix(0,nrow=n2,ncol=2)
  i <- 1
  for(i in 1:length(pc)){
    t1 <- table(factor(phat>pc[i],levels=c(T,F)),Yx[ind,1])
    m2[i,] <- c((t1[1,2])/sum(t1[,2]),1-t1[2,1]/sum(t1[,1]))
  }

return(sum((m2[1:(n2-1),1]+m2[2:n2,1])/2*(-m2[2:n2,2]+m2[1:(n2-1),2])))
}
b1 <- boot(cbind(Y,x1,x2), AUC, 1000)